For Mr Packer, the plunge means the value of his 364 million shares has fallen from $5.83 billion to $5.37billion. He controls just more than 50 per cent of Crown.

Pricey week for a billionaire: James Packer. Photo: Reuters

On Friday, Crown shares fell 43¢, or 2.8 per cent, to $14.75.

Although the shares have tumbled since Monday, when Crown told the market it had outlaid $US280 million ($303 million) for its Vegas property, Friday’s falls are more than likely tied to a weaker-than-expected result for Mr Packer’s joint venture in Macau.

Melco Crown, in which Crown and its partner Lawrence Ho each control 33.6per cent, reported a 20per cent fall in net income to $US143.6million for the three months to June 30.

The result delivered earnings a share of US26¢, which was below the US36¢ a share gaming analysts were expecting.

Mr Ho, Melco’s chief executive, said the company had expanded its share of mass-market gaming and this would continue for the rest of the year, due to the company’s premium assets, table and room optimisation and product enhancements.

The result is sure to rattle investors, despite the announcement of a $US500 million share buyback to hold up Melco’s share price.

Melco shares on the Hong Kong exchange fell 4.8 per cent to $HK78.65 late in the week.